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Nalates Urriah

Exodus Viewer Feature Explanations

Thursday a new post appeared on the Exodus Viewer blog explaining two features of this new viewer. HDR and FXAA. I had guessed, wrongly, that the HDR was High Definition Render. It is High Dynamic Range. My guess average is sliding down…

Exodus Viewer

The article provides a good explanation of the subject terms HDR and FXAA. But, they don’t explain all the terms they use, like MSAA and others. So, I’ll give a try at an explanation too.

HDR

HDR or HDRI is High Dynamic Range Imaging. Exodus explains it and you can find more detailed information in the Wikipedia: HDRI.

If you have used film based photography or the older digital cameras you have run into RANGE problems. Neither could handle the range of bright and dark the eye can see. So, photographs and digital images never looked quite real because we could not see detail in the bright or dark areas of a picture. The top edge of tire in a car’s wheel well would disappear into the black of the wheel well.

Photoshop users can correct the problem to some extent using LEVELS or CURVES.

HDR corrects that problem and the top edge of the tire we can see iRL also appears in the picture. On good HD-TV’s with HDR showing video captured with HDR cameras one gets the strong impression of looking through a window. Most people are just wow’ed and have no idea why the image looks so life like. The reason is the bright to dark range in HDR images more closely provides what the eye expects.

The Exodus team is providing controls to allow us to manipulate how the viewer will render the scene. Adding Red, Green, and Blue controls to the viewer gives one the ability to do fun things with the viewer image, like simulate night-vision goggles.

FXAA

Fast Approximate Anti-Aliasing is a replacement for the Anti-Aliasing (AA) used in many video and image processing pipelines. The Exodus team tells us this is a coming feature for LL viewers.

I have an article, Graphics Tweaking for Second Life, that explains most of the various graphics features we deal with in SLViewers. Well… I link to the tutorials that do. I do link to an image about AA at TweakGuides; AA Page. AA is all about removing the jaggys or stair stepped edges. If you are a beginner to graphics settings this guide explains the basic basics, start at the beginning.

Video cards are taking some new approaches to how AA is done. FXAA is one of those approaches. AA in general is computation heavy. New graphics cards deal with it efficiently, so it is not a major issue. But, faster is better. Tom’s Hardware has a newer article on Anti-Aliasing: Anti-Aliasing Analysis, Part 1: Settings And Surprises.

MSAA (Multi-Sampling AA) is what I understand is currently used in SLViewers. It is less computation intense than Super Sampling AA, which many video cards use. The article at Tom’s shows all the various processes compared. Whether you have an nVidia or ATI card you want to read the article and learn Tom’s information for tweaking your video card. They get into dealing with game settings and problems and benefits from overriding them with card settings.

Summing Up

People report that the Exodus viewer is fastest with Deferred Render enabled.

If you play in RP/combat games in SL, you want the fastest possible frame rates. Exodus’ orientation to combat play may lead to a fast, high quality imaging render engine. So, far it sounds good.